Hold-down lock for pressing heads



June 5, 1951 L. N. STRIKE 2,556,009

HOLD-DOWN LOCK FOR' PRESSING HEADS Filed Sept. 22, 1948 2 Sheets-Sheet 1 Zinnentor 100/5 /V STRIKE Gttorneg L. N. STRIKE HOLDDOWN LQCK FOR PRESSING HEADS June 5, 1951 2 sheets-sheet 2 Filed Sept. 22, l948 L lows/V 5TR/KE 4 3 54 32 g 55 3 m (Ifiorneg Patented June 5, 195 1 UNITED STATES PATENT OFFICE HOLD-DOWN LOCK FOR PRESSING HEADS Louis N. Strike, Salt Lake City, Utah Application September 22, 1948, Serial No. 50,611

This invention relates to a releasable locking mechanism for the pressing head of a pressing machine.

In pressing machines, the padding, the head and the buck thereof wear and/or compact over long periods of use. Also, items of clothing, that may vary considerably in thickness, are passed through such machines. Consequently, the press ing relationship of the head and buck varies to such a degree that conventional latches or looks, having only one hold-down position for the head, cause pressing pressures that are at times too great and at others, too light.

The present invention has for its primary object to provide novel and improved hold-down means that automatically locks the head and buck in proper pressing engagement and according to the thickness of the padding on said head and buck and the thickness of the item being pressed therebetween.

Another object of the invention is to provide hold-down means of the character indicated that automatically assumes one of a multiplicity of locking positions to insure uniformity of pressing pressure under variable conditions.

Another object of the invention is to provide novel means for releasing the hold-down means from any of its locking positions.

The invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawings merely show and the following description merely describes one embodiment of the present invention, which is given by way of illustration or example only.

In the drawings, like reference characters designate similar parts in the several views.

Fig. l is a side elevational view, partly in section, of a pressing machine in closed pressing position and embodying the novel means of the present invention.

Fig. 2 is an enlarged vertical sectional view as taken on line 2--2 of Fig. 1.

Fig. 3 is a similar View showing the parts in the position they assume when the pressing head and buck are separated or in the open position.

Fig. 4 is a top plan view of the mechanism shown in Figs. 2 and 3. l

6 Claims. (Cl. 38-36) Fig. 5 is a fragmentary view, similar to Fig. 2, of a modification.

Fig. 6 is an enlarged fragmentary detail sectional View of an alternate form of clutch element employed in the invention.

The press that is illustrated is generally conventional. The same comprises a frame 5 that mounts a fixed buck 6 and has a pivot I for a.

pressure arm 8 on which is carried a pressing head 9. A spring l0, fixed, at one end, to the frame and, at the other to arm 8 normally exerts a pull on said arm to hold head 9 elevated, or spaced from the buck 6. A handle I! provides means for swinging said arm on its pivot to bring the head and buck into pressing engagement. A foot treadle i2, pivoted at l3 to the frame, through a link I4, a rock arm I5, pivoted to the frame at it, and a second link I1, is provided for exerting foot pressure on the end of arm 8 that is on one side of pivot 1, to cause desired pressing pressure between the head and the buck. A spring iii, extending between treadle I2 and rock arm 15, is placed under tension when said treadle is depressed and, therefore, has sufiicient power to break the nearly straight angle that is formed between rock arm 15 and link [1, thus permitting spring Hi to become effective to elevate the pressing head. In addition to the usual work table l8, the press is provided with means for conducting steam to the head and buck which, for reasons of clarity, have been omitted from the drawings.

The press above described is provided with automatic hold-down means 25 that is, in part, carried by treadle l2, and, in part, by frame 5, and with pressing head release means 21! that includes a release foot pedal 22, a release hand lever 23' and linkage 24 operatively connecting said pedal and lever.

The hold-down means 2i comprises a looking or clutch bar 25 that is mounted on a pivot 26 on treadle it at a point adjacent the front of press frame 5. Said bar has a generally vertical position and the same is formed with a narrow part defined, at one side, by a face 21 and with a wider upper part defined, at the same side, by a face 28. The sloping face 29 connects faces 21 and 28.

The hold-down means further comprises a looking plate 3t mounted on a pivot 3| carried by a bar 32, the latter extending across the front of frame 5, said pivot being transverse to pivot 26 of the clutch bar. A slot 33 is milled from one side into the locking plate to form parallel angular faces 34 and 35 Which are so spaced that, with the oppositeface 38 of the locking bar.

said locking plate at right angles or normal to bar 25, the narrow part of the latter will freely move in slot 33 While the Wider part will be just too wide to fit between the corner 36 of wall 34 and the corner 31 of wall 35. Said two corners are, thereby, adapted to impinge on face 28 and It will be evident, then, that when bar is moved down from the position of Fig. 3 to that of Fig. 2, the locking plate will assume a slight angular position to accommodate the wide part of the bar. It will also be evident the release of treadle I2, after the same has been moved to move bar 25 down, will result in Spring I8 Seeking to elevate the treadle and thereby raise said bar.

' However, this return of the treadle is prevented horizontal position, tilting upward on its pivot to more firmly impinge corner 35 and 3'! into the opposite faces 38 and 28 thereof. Consequently; the treadle I2 and therefore the pressing head 9, are locked in the down position of Fig. 1, and will remain in that position until released.

It will be noted. that variations in the thickness of the padding of the pressing head and buck and also variations in the thickness of an item 39 that is being pressed, results merely in corners 36 and 3? impinging on different portions of faces 38 and 28, the lock being efiective anywhere along the upper wider portion of the looking bar.

The release means 2| comprises a rod 40 that is pivotally'connected at III, to release pedal 22 slightly forward of the pivot c2 of saidpedal on frame 5. A spring 43 normally holds the foot-engageable part of said pedal elevated and, therefore, the rod 46 in a raised position. The

latter extends through a hole 44 in the free endof locking plate 3!], said hole being conically formed to permit the mentioned angular movement of said plate. Adjustable stop nuts .45 are provided on the protruding part of rod 40 above plate 30, similar stop nuts 45 are provided on an intermediate part of said rod, and a compression spring 41 has abutment at one end, with nuts 46, and, at the other, with the under side of plate 30. The nuts 45 and 45 are so adjusted that spring 41 is under compression to hold plate 30 against nuts 45 in at least a horizontal position, although a slight upward angular position of said plate is immaterial to the function.

, The manual lever 23 is pivoted at 48 to arm 8 so that the same is adjacent to handle II or, at least convenient to the hand of the operator. A bell crank lever 49 of linkage 24 is mounted on pivot I for free movement, one arm thereof is connected by a link 59 to a rearward extension 5| of pedal 22, and the other arm thereof the pressing head 9 to raised position with respect to buck 6.

Since the pivot 26 for the locking bar 25 moves'in an arc around pivot I3 of treadle I2,

a suitably designed projection 53 is provided on said bar to have sliding engagement with base wall 54 of slot 33 and maintain said bar substantially upright in any of its positions. Said projection is curved to be deeper near its lower end, to thereby urge bar 25 in a direction outwardly of slot 33 when treadle I2 is elevated and pivot 26 has a position real-wardly offset with respect to said slot and the walls thereof. The upper end of projection 53 is shallower to allow bar 25 to move deeper into the slot as the pivot 26 moves forward during foot depression of the treadle. It will be seen that the bar 25 retains a substantially upright condition for all positions thereof.

It will be seen that pivots 25 and 3I are transverse to each other and that bar 25 and locking plate 30 move in respective planes that are transverse to each other.

The arms of hell crank lever 49 are made as short as practicable. However, some movement in linkage 24 occurs when the head is moved to pressing position. Such movement, no matter how small, results in depression of rod 40. Consequently, nuts 45 are preferably set sufiiciently high on rod 40 so that this depression of said rod will cause nuts 45 to move plate 39 to the mentioned horizontal position where the effective distance between corners 35 and, 31 is smaller than the width of the upper portion of locking or clutch bar 25. By this arrangement, only a small motion of pedal 22 or lever 23 is required to further depress rod 43 to downwardly tilt plate 30 and thereby effect release of the clutch bar.

The normal necessary changes in the adjustment of conventional locking or hold-down means are unnecessary in the present automatic hold-down means, since the same seeks its locking position according to a variety of conditions in the press.

In the modification of Fig. 5, the plate 30 is urged in an upward direction by a tension spring 41a connected between the end of said plate and a cross bar 32a similar to and above bar 32. The threads on the end of rod 40 are thus shorter and are provided only for the stop nuts 45, the nuts 46 being omitted. Instead of the angular mill cutthat forms the corners 36 and 31, a straight and square mill cut, as shown in Fig. 6 may be made in plate 30 and hardened steel cylindrical rods or pins 55 and 56 are tightly fitted in suitable reamed bores to laterally extend into the cut and provide the gripping points for clutchbar 25. Thusyany wear on said pins 55 and 56 may be compensated for by a rotational adjustment thereof, a kerf or the like being provided at the end of each pin for a rotating tool.

While I have illustrated and described what I now regard as the preferred embodiment of my invention, the construction is, of course, subject to modifications without departing from the spirit and scope of my invention. I, therefore, do not wish to restrict myself to the particular form of construction illustrated and described, but desire to avail myself of all modifications that may fall within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A hold-down lock for a pressing head comprising a clutch bar having spaced gripping and non-gripping portions, means for pivotally mounting said bar for movement in one plane between two end positions, and a locking member pivotally mounted to move in a transverse plane and having a slot in which said bar moves, said slot being defined by opposed parallel walls that are at an angle to the general disposition of the clutch bar to present respective upper and lower corners adapted to impinge opposite faces of the gripping portion of said bar.

2. In a hold-down lock of the character described, a longitudinally movable clutch bar having a narrow portion and a wide portion and a tiltable plate having a slot in which said bar is movable, said slot being defined laterally by opposed bar-gripping portions and said portions being offset relative to the horizontal, said portions comprising cylindrical hardened members having l their cylindrical faces extending into the slot and adapted to be rotationally adjusted whereby worn portions of said faces are adapted to be replaced by unworn face portions.

3. A hold-down lock for a pressing head and the like, comprising a pivoted treadle, a substantially upright clutch bar pivotally carried by the treadle, the pivot of the clutch bar being adapted to move in an arcuate path in a plane around the pivot of the treadle, a locking member mounted on a pivot transverse to the pivot of the clutch bar, said locking member being movable on its pivot in a plane transverse to the plane of movement of both the treadle and clutch bar, said locking member having a slot into which the clutch bar extends and said slot having a base wall, an edge-curved projection on the clutch bar for engaging said base wall and thereby moving said clutch baron its pivot during arcuate movement of said pivot to maintain the clutch bar substantially upright, and said slot having opposed gripping portions adapted to grip the clutch bar therebetween.

4. The hold-down lock according to claim 3 in which the opposed gripping portions comprise rotationally adjustable hardened members that extend laterally into the slot of the locking memher to grip the clutch bar.

5. The hold-down lock according to claim 3 in which the projection on the clutch bar is deeper at a point nearer the clutch bar pivot and shallower at the remote end thereof, whereby the clutch bar is deeper in the slot when the shallower part of the projection is engaged with the base wall thereof and partially displaced from the slot when the deeper part of the projection is so engaged.

6. In a hold-down look, a substantially upright clutch bar having a pivoted end adapted to move in an arcuate path and having a clutch. portion on the opposite end, a transversely pivoted locking member having an open-sided slot into which the clutch bar extends and through which the same is adapted to move during movement of the pivoted end thereof in the mentioned arcuate path, and means to maintain said clutch bar substantially upright durin movement thereof, said means comprising a base wall of the slot in the locking member and an edge-curved 1ongitudinal projection on the clutch bar and slidably engaged with said base wall, the opposed walls of said slot having portions adapted to grip the clutch portion of the bar.

LOUIS N. STRIKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,853,517 Finnerty Apr. 12, 1932 1,868,934 Zacharias July 26-, 1932 2,014,300 Strobridge Sept. 10, 1935 

